Skin Patch Shows Promise for Delivery of Influenza Vaccine

Researchers at the University of Rochester Medical Center in New York City have developed a new type of skin patch that could replace needles as a method to deliver the influenza (flu) vaccine. While previous flu vaccine skin patches used microneedles and electroporation, which are difficult to implement on a large scale for mass vaccination, this new patch uses a protein to make the skin barrier that normally prevents toxins and allergens from entering the body more permeable. The approach came to researchers when they investigated the biology of eczema. People with eczema have low levels of claudin-1 that causes the skin to become “leaky.”

In the study, the researchers created a skin patch containing a peptide (small protein) that binds to and blocks claudin-1, and a recombinant flu vaccine and tested it in two ways on mice. In the first test, they applied the skin patch and then gave the mice a flu vaccine by injection to prime the immune system with the patch and then boost immunity with the vaccine. In the second test, the researchers gave the mice the flu vaccine first and then applied the skin patch to prime the immune system with the vaccine and then boost it with the skin patch. In both tests, the patch opened the skin barrier, which was confirmed by monitoring the amount of water the mice lost through their skin. When they applied the patch, the mice’s skin became permeable, and when they removed it, the skin began to close, getting back to normal within 24 hours. While the immune response to the patch in the first test was insignificant, there was a robust immune response to the patch in the second test.

According to the researchers, since humans are exposed to influenza as young as 6 months of age and, therefore, most people’s immune systems are already primed to the virus, the second test best mimics a real-world scenario, suggesting the patch could serve as a delivery mechanism for the regular seasonal flu vaccine. Notably, there were no side effects. After monitoring the mice for three months, there was no physical change in their skin such as might arise from infections. Studies are still needed to determine how long the patch should remain on the skin for optimum results.